after riding my 400 ex with VERY low hours on it today I noticed the same thing, as it got hot it had a bit of motor noise, don't worry it's pretty normal, NOT the cam bolts!!!!!!!!!!!!!!!

 

I do believe he said loud noise. Normal is not loud. Does the tapping become more frequent with the higher the rpm's? In my case the bolts had backed out of the timing chain sprocket and the two of them would click every time they hit the head cover(valve cover)gasket. Possibly could be the auto decompress. Does it make this noise as soon as it is started?

 

I drove a brand new 400EX that had occasional rattling and grinding noises. The owner sold his 400EX soon after. I bought mine at the same time and its always been as quiet as can be.

 

Yeah, the ticking noise will increase with the engine rpm's. It only seems to do this when the motor is completely warmed up. That's why I was thinking something with the valves.

 

You should definitely get it checked out. It is not normal.

 

jcv400ex,
If you ride HARD or if you used to ride a 2-stroke, do not use synthetic oil. It glazes the clutch fibers promoting slippage and early failure. I should know, I'm on my 3rd clutch and have had no problems since going non-synthetic. I also have a 440 now and the extra power hasn't smoked the clutch either. Honda's GN is good oil and it's much cheaper. If you are changing your oil at the proper intervals, you'll be fine.

 

what grade do you use? Currently i'm using 10w40.

 

SUP440,

thanks for the help. I'm just loading it up tonite and taking it down. I'll keep ya posted on what it was.

thanks agian

 

10W40. In the dunes I run 10W50.

 

My 350X made a ticking like you described. It turned out to be the decompression mechanism. I am not sure if it is similar on the 400EX.